OBJECTIVE:
To analyze the increase in number of authors per article in Brazilian scientific
journals on public health.METHODS: Articles published between 1999 and 2010 in six journals on
public health and one medical journal (for comparison) from SciELO with Qualis
(Capes) classification equal or superior to B-1, were searched on the LILACS
database. The evolution of the median number of authors/article and the proportion
of articles with more than four authors were evaluated. The association between
the the triennium of publication and the presence of four or more authors per
paper was estimated through the Mantel-Haenzel odds ratio, adjusted for
the type of journal.RESULTS: An increase of the median number of authors and the proportion
of articles with more than four authors was observed in all journals, especially
in the last triennium. The odds ratio for articles with four or more
authors, adjusted for the type of journal, were: second triennium 1.3 (95%CI
1.1;1.4); third triennium 1.5 (95%CI 1.3;1.8), fourth triennium 2.39 (95%CI
2.1;2.8).CONCLUSIONS: Scientific journals on public health have shown an increase
in the number of authors per article over the years, regardless of editorial
orientation.

The number of authors
per article has increased in scientific journals, a peculiar worldwide phenomenon
in recent decades. Studies using different techniques, involving diverse journal
groups and varied reference periods have unequivocally verified this fact.1,
8,15,18,22 One of these studies24 quantified the authorship
of millions of articles in five decades and showed that such phenomenon occurs
in all areas of knowledge, including the social sciences, albeit with less intensity.

Most of these studies
merely identify and describe the phenomenon, but there are those that seek to
understand its determinants.2,5,12,17,23 Analysis performed on a
sample of authors of 896 articles published in leading medical journals (Annals
of Internal Medicine, JAMA, Lancet, Nature Medicine, New England Journal of
Medicine and PLoS Medicine) showed a reasonable proportion (17.6%) of cases
in which individuals who were included as authors had not contributed sufficiently
to merit this designation, characterizing the so-called "honorary authorship".
Considering only research articles, this proportion reached 25%.

One of the mentioned
studies5 showed that the main contribution to the growing number
of authors per article in the British Medical Journal (BMJ), over 20 years,
was the relative increase in the number of senior authors. This finding becomes
worrying in the view of the "white bull effect" (a reference to the myth of
seduction of Europa by Zeus, disguised as a white bull), described by Kwok14
as the self-imposition of a given individual as "honorary author" to a researcher
in a weaker position. For instance, the negotiation of senior researchers with
students under their guidance. How much of the senior authors' contribution
in the study on the BMJ articles would be attributable to the "white bull" is
something that must be questioned.

A frequent explanation
for the increase in the average number of authors is that the greater complexity
of studies would demand more and more cooperative work.1,7,8,17 While
this is possible and even probable, Papatheodorou et al17 disagree
that this fact explains all the situations in which such an increase is observed.
Their research showed an increase in the number of authors over the years, in
both randomized and non-randomized studies, with the effect of year of publication
remaining significant after adjustment for other factors, such as the topic
of study, multinational study and population size.

One reason for
the growing number of authors would be the answer to the pressures on researchers
to increasingly publish articles (the so-called "publish or perish"). However,
in some situations a large number of authors is justified, including multicenter
and/or multidisciplinary studies, and research involving complex and laborious
designs. Therefore, the analyses presented are justified to protect and adequately
characterize these situations.

Such considerations
led to the question: Would this growth also be observed in Brazilian journals
on public health?

Hence, the objective
of this study is to analyze the increasing number of authors per article in
Brazilian scientific journals on public health.

METHODS

A study was carried
out in 2010 with Brazilian journals on public health included in the ScieLO
collection, with classification Qualis/CAPES equal or superior than B1: Revista
de Saúde Pública (RSP), Cadernos de Saúde Pública
(CSP), Ciência & Saúde Coletiva (C&SC), Revista Brasileira
de Epidemiologia (RBE), Physis e Interface. The Brazilian Journal of Medical
and Biological Research (BJMBR), also holding a Qualis B1 classification in
public healthª (2010) and
found in SciELO, was included for comparison. For each journal, all references
in the LILACS database (1999 to 2010) were selected. The initial year of the
period was chosen for the journals that were already being published for at
least one year, and 2010 represented the last year with all issues published
and present in the database at the time of the review.

The references
were exported in RIS format and the number of authors per paper was calculated
by an application developed for this purpose. Analyses were performed according
to the four triennia of the studied period to ensure a greater stability in
the estimates. The median number of authors per article (interquartile range)
and the proportion of the number of articles with four or more authors were
calculated for each triennium. The association between the triennium of publication
and the presence of four or more authors per paper was estimated through the
Mantel-Haenzel odds ratio, adjusted for the type of journal. The journals were
grouped into four categories3: 1) clinical journal (BJMBR); 2) journals
with a higher proportion of epidemiological articles (RBE, CSC, RSP); 3) journal
without a clear predominance of a specific study field (C&SC); 4) journals
with a higher proportion of articles on the humanities (Physis and Interface).
The analyses were performed with the Stata program (version 9.0).

RESULTS

A higher median
of authors for the BJMBR, followed by group 2 journals (RBE, CSC, RSP), was
observed in all periods (Table 1).
Group 4 (Physis and Interface) and group 3 (C&SC) journals had the lowest
medians. An increase in the median number of authors in the last triennium was
observed for all journals, when compared to the first triennium. The proportion
of articles with four or more authors had a roughly similar distribution to
the median of authors related to journal category, although C&SC has shown
higher proportions than the group 4 journals for this indicator (Figure
1). The growth of this proportion was observed for all journals analyzed.
Taking the first triennium as a reference, the odds ratios are presented for
articles with four or more authors, adjusted according to journal group (Table
2). This analysis also reveals growth. The chance of having four or more
authors was 2.39 higher for articles published in the last three years compared
to those published in the first three years (Table
2).

DISCUSSION

An increase in
the number of authors per paper was observed, particularly in the last triennium,
based on two indicators: median number of articles and proportion of articles
with four or more authors.

As this phenomenon
is confirmed in the analyzed journals, a question remains: Is it the result
of an increased cooperation between Brazilian authors or "honorary authorship"?

The possibility
of undue authorship has taken various editors to express their views over time.9-11,19,21
An editorial published in Nature9 reports the difficulty of finding
mechanisms to control the situation. Another10 connects this problem
with the use of quantitative indicators of scientific production, as the productivity
incentive would lead to the proliferation of authors as a way to cheat the system,
at least partially.

A particularly
intense exchange began after a joint editorial by the then editors of Lancet
and BMJ11 (Richard Horton and Richard Smith, respectively), who analyzed
their concerns regarding this problem, and announced a seminar to discuss proposals
to address the situation. An editorial in the BMJ19 points to a radical
strategy, based on the discussions from the seminar previously mentioned: articles
would have contributors instead of authors, who would be identified according
to their participation, just as in the credits of a movie. To ensure ethical
responsibility on the printed content, the articles would have a "guarantor".
These ideas prompted the then editor of the American Journal of Public Health
(AJPH), Mervyn Susser, to publish an editorial21 that endorsed such
proposal, asking the readers for their opinions. Responses were published in
the May 1998 issue, occupying practically the entire letters section of the
AJPH. The positions were varied, and no consensus was reached.

Publications4,6,7,16,20
make revisions of proposed solutions, trying to offer control models to limit
the possibility of undue authorship. Such solutions are divided into two major
groups, both based on exhaustive lists of possible actions (contributions) in
the making of an article. The first treats the list as a checklist, requiring
minimum number of contributions (usually three) for the authorship to be considered.
The other works with complex score systems assigned to each type of contribution,
requiring a minimum total value, which varies according to the scheme adopted.
One of the consulted papers13 sought to evaluate the operation of
such schemes. The authors of 181 articles published in the Croatian Medical
Journal, from January to July 2005, were consulted, by randomly using instruments
based on the checklist or scoring system. It was concluded that the latter was
more sensitive for determining authorship.

These proposals
are attempts to implement the minimum requirements for authorship by the International
Committee of Medical Journal Editors (ICMJE),b
which states that "authorship credit should be based on 1) substantial contributions
towards the conception and design, data acquisition, or analysis and interpretation
of data; 2) article writing or critical revision with important intellectual
content; and 3) final approval of the version to be published. Authors should
meet conditions 1, 2 and 3." This guidance resulted from the discovery of a
fraud case (known as "Darsee affair") in the 1980s, which exposed several cases
of "honorary authorship".19

One review article
analyzed16 points out to usual and mistaken roles for attributing
authorship, such as being administratively in charge of a research group or
department, and raising funds for a project without being involved with it otherwise.
In addition, there are other roles that could be acknowledged, but no authorship
would be given to those revising or editing a manuscript, performing manual
data collection (exceptional circumstances could change this), cleaning data,
as well as providing resources (e.g. reagents or basic processes involved in
the research that have not been specifically developed for it), basic maintenance
and management of equipment/instruments (equipment/tools developed specifically
for the considered project could, nonetheless, qualify for authorship). The
studied journals adopt the ICMJE criteria with small systematic variations,
demanding the authors a statement of authorship responsibility, without presenting
any kind of checklist or score.

The CNPq itself
recently reported problems in the dissemination of scientific research under
its funding. Considering that overcoming such problems would require the formulation
of specific internal rules, nonexistent at that time, a committee responsible
for their elaboration was created. Their publication on the organization's website
followed.c Several rules
relate to the question of authorship (referring to the ICMJE criteria), indicating
that, at least, there is some concern over this issue in our circles.

We emphasize that
there are multiple authors per article, and even though the average number of
authors is growing, it does not translates as an irregularity. The scientific
work becomes more complex with the development of major projects. In health
sciences, and particularly in public health, increasingly large databases are
created, requiring more sophisticated strategies for extracting relevant information,
or able to articulate diverse data and/or material sources (biobanks, collections
of genetic profiles). Therefore, the appearance of larger research teams is
inevitable, and this will tension the definition of what exactly qualifies for
authorship. The growing complexity of research, with multiple insertion possibilities,
even without undue manipulation, creates difficulties in defining who can appear
as an author in a given publication, and this is not adequately discussed by
Brazilian authors and editors.

It is not possible
to determine, due to the limitations of this study, whether or not the honorary
authorship was occurring in the publications analyzed. The increasing number
of authors per article, regardless of the journal's editorial orientation, indicates
the need to further explore this issue through more extensive studies that include
other variables, allow to qualify more precisely the type of study that originated
the article and also assess authorship qualitatively.

Particularly in
the absence of effective controls, the attribution of "honorary authorship"
may be a considerable temptation in an environment which stimulates the production
of increasing numbers of articles. It is a task for editors, authors and readers
to ensure compliance with the ethical principles governing authorship, thus
avoiding the situation when the basic currency of academic credibility will
suffer from inflationary devaluation, as expressed by Papatheodorou et al.17
These authors made a clear allusion to what repeatedly occurred in recent decades
with certain products under accelerated growth: the collapse of their markets,
showing that their apparent value was unreal, an inflationary bubble.

16. Osborne JW, Holland A. What is authorship, and what should it be? A survey of prominent guidelines for determining authorship in scientific publications. Pract Assess Res Eval. 2009;14(15):e15. [ Links ]

17. Papatheodorou SI, Trikalinosa TA, Ioannidis JPA. Inflated numbers of authors over time have not been just due to increasing research complexity. J Clin Epidemiol. 2008;61(6):546-51. DOI:10.1016/j.jclinepi.2007.07.017 [ Links ]